Count Operations to Obtain Zero

给两个数字, 大减小, 求多少步能减到0.

class Solution {
    public int countOperations(int a, int b) {
        if(a == 0 || b == 0)
            return 0;
        if(a > b)
            return countOperations(a - b, b) + 1;
        else
            return countOperations(a, b - a) + 1;
    }
}